Mary Landrieu and other red-state Dems could be in trouble when voters get to them. Photo: AP

In the hours since the federal government shut down, almost all attention has zeroed in on House Republicans, who have neither defunded nor delayed ObamaCare.

Certainly it’s not clear how Speaker John Boehner comes out a winner. But amid all the barely disguised glee that the GOP will be stuck with responsibility for closing down the government, almost no one has noticed the problem Senate Democrats have created for themselves.

Little more than a year from now, the Senate will be up for grabs. Of the 33 seats that will be contested in 2014, roughly two-thirds are held by Democrats. If they lose five, they lose their majority.

Now think about that in terms of ObamaCare. Sure, it’s easy for Majority Leader Harry Reid, who won’t face re-election until 2016, to demand Senate Democrats reject any compromise on ObamaCare — even a medical-device tax many Senate Democrats claim to oppose — just to force Republicans into a shutdown. But the votes taken Monday night may be tough ones for Democrats up for reelection in 2014.

How, for example, will Louisiana’s Mary Landrieu respond when her GOP opponent points out she opted for a shutdown instead of giving up special treatment for herself and extending to individual Americans the same exemption President Obama gave to his corporate pals?

She’s not alone: Mark Begich in Alaska, Mark Pryor in Arkansas and Kay Hagan in North Carolina will all have to answer the same questions. And what about the non-controversial spending bills the GOP pushed Tuesday night to fund national parks and veterans affairs and local DC government? House Democrats blocked the two-third majority they needed to pass? Is this absolutism really going to be a Democratic selling point, especially if ObamaCare’s unpopularity continues ­to grow?

We don’t pretend to know how this impasse will end. But the question no one seems to be asking about Senate Democrats is not how this plays out today, but how it will look in November 2014.